1. Field of the Invention
This invention relates to a launcher for a ring airfoil projectile.
2. Description of the Related Art
There are a number of devices for launching projectiles.
U.S. Pat. No. 4,154,012 employs a rod within a barrel to facilitate the launching of a grenade.
U.S. Pat. No. 4,291,663 has a rod containing a helical groove for launching a ball that spins as it moves longitudinally. Lines 63 through 65 in column 3 declare, xe2x80x9c. . . the rod 18 is a hollow cylinder with a long, thin aperture 51 describing a portion of a helical path about its exterior.xe2x80x9d Furthermore, lines 9 through 14 in column 3 explain, xe2x80x9c. . . the trigger operating device 22 presses against the trigger (not shown in FIG. 1) of the launcher 24. This releases the launcher 24 which is spring driven to impel the ball 28 along the length of the rod [member] 18 and cause it to be thrown in a line in the direction of the axis of the rod 18.xe2x80x9d And lines 31 through 35 in column 4 indicate, xe2x80x9cIt should be noted that in the preferred embodiment the launcher 24 travels a helical path described by the aperture 51 so that a spin is imparted to the ball.xe2x80x9d
U.S. Pat. Nos. 5,970,970 and 6,079,398 both cover a launching rod having a fixed helical groove or aperture to launch a ring airfoil with a spin having been imparted to the airfoil through interaction of the launch platform with the groove.
The disclosure of U.S. Pat. No. 5,970,970 also explains, xe2x80x9cPropelling element 62 is associated with ring airfoil support 60 and is configured to move the ring airfoil support along member 58. Such movement may involve acceleration and deceleration. Propelling element 62 is best seen in FIG. 8. In launcher 20, propelling element 62 takes the form of a spring having two ends, where one end is attached to a knob 82 inside the forward end of member 58 and the other end is attached to pin 78 as it passes through member 58.xe2x80x9d
U.S. Pat. No. 5,970,970 further clarifies, xe2x80x9cTrigger 28 . . . holds ring airfoil support 60 in the first, cocked position, in which energy is stored in the launcher, and releases ring airfoil support 60 upon actuation of the trigger to permit the ring airfoil support to move along member 58 to the second, fired position, in which energy is transferred to the ring airfoil.xe2x80x9d
Finally, the disclosure in U.S. Pat. No. 5,970,970 says, xe2x80x9cMember 58 also may have a channel 68 disposed along at least a portion of its length. This channel may take a number of forms. In launcher 20, channel 68 takes the form of two helical slots disposed on opposite sides of member 58 and making about one-quarter turn along the length of the member.xe2x80x9d It does not appear that any other embodiment is described in U.S. Pat. No. 5,970,970 for causing the airfoil to rotate.
And U.S. Pat. No. 6,079,398 provides, xe2x80x9cfurther secured over forward end 140 is a launch spring 148 (illustrated as a cylinder and preferably a metal coil spring) and a launch chuck 150. Chuck 150 includes a sleeve portion 152 having an inner diameter 154 in which a pair of tabs (not shown) are formed. The tabs engage slots 138. Slots 138 form a helical twist which causes a rotation of chuck 150 as it moves axially along shaft 100. Launch spring 148 bears between collar 142 and chuck 150, and chuck 150 is retained on forward end 140 by a bumper 156 and a retainer 158 that is secured to forward end 140. Chuck 150 is formed with a plurality of radially outwardly extending arms 160, that are adapted to engage inner surface 46 of a ring airfoil 34, and outwardly extending tabs 162 adapted to engage trailing edge 45 of ring airfoil 34.
None of these patents provide for altering the degree of spin.
In the airfoil launching system of the present invention the rotation of the airfoil is adjustable and is accomplished with two or more resilient bands. The degree of axial rotation is determined by the amount which a spin guide is rotated about the longitudinal axis of the launch guide. The two resilient bands are angularly rotated by the spin guide to the same extent as is the spin guide.